Yes, exactly, heat transfer rate! Especially for when small amounts of hot water are needed an existing system would need to get very hot very fast because it's transfer rate is poor. That would draw more power than a system that only does the minimum necessary. And once water is not needed anymore a lot of that heat would still be there in the elements. For longer uses I would guess the differences would be smaller since once a traditional system gets warmed up whatever heat is there will ultimately get transferred to the water at some point. And the elements may even switch off completely with a thermostat in some systems if they are hot enough for what is needed, which the magnetron would not be able to do. I would assume other losses, like heat to the environment through the enclosure and the resistance of the components would be similar to existing systems.
Anyway, at this point we will know soon enough what the deal is. And i don't think there needs to be a huge improvement in the bottom line cost of ownership and operation (which is really what matters in the end the most) for this thing to be a success. The market is huge, even if only considering home water heaters and there are so many other uses.
Market Data 
Markets 
AI
